Fig. 1 Cumulative vertebrate species recorded as extinct or extinct in the wild by the IUCN (2012). Graphs show the percentage of the number of species evaluated among mammals (5513; 100% of those described), birds (10,425; 100%), reptiles (4414; 44%), amphibians (6414; 88%), fishes (12,457; 38%), and all vertebrates combined (39,223; 59%). Dashed black curve represents the number of extinctions expected under a constant standard background rate of 2 E/MSY. (A) Highly conservative estimate. (B) Conservative estimate.
Fig. 2 Number of years that would have been required for the observed vertebrate species extinctions in the last 114 years to occur under a background rate of 2 E/MSY. Red markers, highly conservative scenario; blue markers, conservative scenario. Note that for all vertebrates, the observed extinctions would have taken between 800 to 10,000 years to disappear, assuming 2 E/MSY. Different classes of vertebrates all show qualitatively similar trends.
- Table 1 Numbers of species used in the Table 2 calculations of “highly conservative” and “conservative” modern extinction rates based on the IUCN Red List (17).
For the highly conservative rates, only species verified as “extinct” (EX) were included; for the conservative extinction rates, species in the categories “extinct in the wild” (EW) and “possibly extinct” (PE) were also included.
Vertebrate taxon No. of species, IUCN 2014.3 Highly conservative
rates (EX)Conservative rates
(EX + EW + PE)No. of species
evaluated by IUCNSince 1500 Since 1900 Since 1500 Since 1900 Vertebrates 338 198 617 477 59% (39,223) Mammals 77 35 111 69 100% (5,513) Birds 140 57 163 80 100% (10,425) Reptiles 21 8 37 24 44% (4,414) Amphibians 34 32 148 146 88% (6,414) Fishes 66 66 158 158 38% (12,457) - Table 2 Elevation of “highly conservative” and “conservative” modern vertebrate extinction rates above background rate of 2 E/MSY (see table S2 for calculations).
For each assessment category, two periods are shown: extinction rates computed from 1500 to the present, and from 1900 to the present.
Animal group Elevation of modern rates with
respect to expected ratesHighly conservative Conservative Since 1500 Since 1900 Since 1500 Since 1900 Vertebrates 8 22 15 53 Mammals 14 28 20 55 Birds 13 24 15 34 Reptiles 5 8 8 24 Amphibians 5 22 22 100 Fishes 5 23 12 56
Supplementary Materials
Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/1/5/e1400253/DC1
Table S1. Definitions of IUCN categories (17) used to assess modern extinction rates.
Table S2. Estimation of modern extinction rates since 1500 and 1900.
Additional Files
Supplementary Materials
This PDF file includes:
- Table S1. Definitions of IUCN categories (17) used to assess modern extinction rates.
- Table S2. Estimation of modern extinction rates since 1500 and 1900.
Files in this Data Supplement:
